JPS59200811A - Magnetic bearing - Google Patents

Abstract

PURPOSE:To prevent the ring recessed part from deformation during assembling period and the like, and enable to control the accurate rotor positioning by a method wherein a non-magnetic material is embedded in a ring recessed part formed on the opposite surface against a stator of a rotor. CONSTITUTION:A recessed part 6 is formed on the opposite surface against a stator of a rotor 1, the recessed part causes to generate a crosswise attraction force on the rotor against the stator, also causes to generate a restoring force for returning of deviation of the rotor 1 toward previous position. The pole surface of the rotor 1 is made flat by embeding a non-magnetic material 16 such as a stainless material and the like in the recessed part 6, also prevented from the deformation due to contacting and the like during the assembling work. Therefore, a fine processing part for obtaining of stability in radial direction of the rotor 1 is prevented from large deformation, accordingly, the magnetic bearing having excellent performance can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic bearing using a magnet 2 such as a permanent magnet.

Conventionally, there has been a device of this type as shown in FIG.

In the figure, (1) is a rotor made of magnetic material 2, such as iron, in an annular shape, and (21, (3) are first and second stators, which are made of magnetic material and are magnetized in the radial direction. The magnet 9 includes a permanent magnet (4), for example a permanent magnet (5).
The second stator (21, (31) is a control coil wound around the rotor (1).
The brocade 1 is arranged with a predetermined gap (9a) and (9b) between the stators (31) and has a cover (6) on the surface facing the second stator (21, (3). , Z indicates the rotation axis of the rotor (1).

Next, the operation will be explained. Since the permanent magnets (4) are magnetized in the radial direction, the rotor (1) and the first. An annular magnetic flux flow as shown by the solid line in the figure is formed between the second stator (2+, 9b)
has a direction in the negative direction of the z-axis. on the other hand.

The current flowing through the control coil forms a flow of magnetic flux shown by the broken line in the figure, but if the current were to flow from the positive terminal to the negative terminal of the control coil (5), this 11f, the flow (The magnetic flux flow created by the permanent magnet (4) is in the same direction as the magnetic flux flow created by the permanent magnet (4) at the gap (9a), so it is strengthened, and at the gap 2 and 1εφ (9b) it is in the opposite direction, so it is weakened. As a result, the rotor ( 11, there is a strong difference in the suction force in the Z-axis direction, and the rotor (1) is moved in the positive direction of the Z-axis.

Conversely, if current flows from the negative terminal to the positive terminal of the coil (5), the rotor (1
) is moved in the negative direction of the z-axis.

In this way, the first . 2nd stator +2
1, +31 is outputted by a generator (not shown), and this signal is applied to
The radial support of this magnetic bearing, which allows the position of the rotor (11) to be changed in a direction parallel to the axis of rotation by clicking the heft, will now be explained with reference to FIG.

In the figure, (10a) and (10b) are the first. It shows the outer spacing between the second stator (21, (31) and the rotor (1). When the rotor (1) rotates and a deviation occurs in the radial direction as shown in Figure 2r. , the gap (9a) between the rotor (1) and the first and second stators (21, (3))
, (9t+) l (10a) + (10b) also shifts as shown in the figure. At this time, the first. Since the opposing surfaces of the second stator +21 and the rotor (1) are protruded, the magnetic flux flows into the magnetic flux shielding part (6) at the corners of the protrusions of each other, causing lateral attraction to the rotor. As a result, the natural restoring force of the magnetic flux shown by the arrow is applied to the rotor (1), and as it tries to return the displacement of the rotor (1) to its original position, this magnetic bearing will move in the radial direction. stabilized.

In such a magnetic bearing, in order to take measures for stabilizing the rotor (1) in the radial direction, the rotor (11 and the first
．． It is necessary that the opposing magnetic poles of the second stators +2) and +31 have a fine convex shape with a width of several millimeters, for example. However, since this machining is minute, it easily deforms, and the deformation of this convex shape reduces the restoring force against radial deviation due to the rotation of the rotor (1), thereby increasing the performance of the bearing. There were drawbacks.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above. a second stator, a first stator; coaxially between the second stator and the first stator. an annular rotor disposed at a predetermined distance from a second stator; The first stator of the rotor is provided with an annular cover provided on a surface facing the second stator, and a detector for detecting the movement of the rotor. In the magnetic bearing that controls the position of the rotor by detecting the inclination with respect to the second stator, a non-magnetic material is embedded in the cage part. The purpose of this is to prevent deformation of the opposing magnetic poles of the second stator and rotor.

An embodiment of the present invention will be described below with reference to the drawings.

In Fig. 3, tt+9 is the rotor (1) cap (6
) is a non-magnetic metal such as stainless steel.

A non-magnetic material (
By filling the magnetic pole surface of the rotor (1), the magnetic pole surface of the rotor (1) becomes flat and difficult to deform due to contact during assembly of the rotor (1).

Therefore, the finely machined portions that provide stability in the radial direction of the rotor (1) are not significantly deformed, and a magnetic bearing with good performance can be obtained.

In the above embodiment, the non-magnetic material is buried only in the casing of the magnetic pole, but as shown in FIG. 4, the non-magnetic material may be further applied to cover the entire surface of the magnetic pole.

As described above, according to the present invention, the cylindrical first cylindrical first magnet having a magnet. a second stator, a first stator; Between the second stator,
An annular rotor coaxially arranged at a predetermined distance from the eleventh and second stators.

The first rotor of this rotor. The first stator of the rotor is provided with an annular cover provided on the magnetic pole face facing the second stator, and a detector for detecting the movement of the rotor. A magnetic bearing that controls the position of the rotor by detecting an inclination with respect to a second stator.

By burying a non-magnetic material in the cage, the magnetic pole surface of the rotor is protected and performance deterioration is prevented.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional perspective view showing an example of a conventional magnetic bearing;
3 is a cross-sectional perspective view showing a rotor of a magnetic bearing according to an embodiment of the present invention, and FIG. 4 is a sectional view of a magnetic bearing according to another embodiment of the present invention. FIG. 3 is a cross-sectional perspective view showing a rotor. In the figure, (1)... rotor, (2)... first stator. (3)...Second stator, (4)...Magnet, (6
)...Oval part, 06)...Nonmagnetic metal body. In the figures, the same reference numerals indicate the same or equivalent parts. Agent Masuo OiwaFigure 1Figure 2Figure 3Continued from page 10 Inventor Kayoshi Yabuuchi 8-1-1 Tsukaguchi Honmachi, Amagasaki City, Mitsubishi Electric Corporation Production Technology Laboratory ■Applicant Mitsubishi Electric Stock Company 2-2-3 Marunouchi, Chiyoda-ku, Tokyo

Claims (2)

[Claims] (1) Cylindrical first and second stators made of magnetic material and having magnets; first and second stators made of magnetic material; coaxially between the second stator and the first stator. an annular rotor disposed at a predetermined distance from the second stator;
A detector for detecting the commuting of the rotor to a ring-shaped part provided on the magnetic pole face facing the second stator, detects the inclination of the rotor with respect to the first and second stators, and detects the position of the rotor. In magnetic bearings that control
A magnetic bearing characterized in that a non-magnetic material is embedded in the cage portion. (2) A non-magnetic material is buried in the rotor casing, and the rotor and the first. The magnetic bearing according to claim 1, which covers the entire magnetic pole face facing the second stator.